DALLAS (AP) -- Dirk Nowitzki sat at his locker, with a bulging ice bag wrapped around his left ankle and a sly smile across on his face.
The reigning MVP was back in the playoff race for the Dallas Mavericks -- and they got a huge victory in a game that many didn't expect him to play. Nowitzki wasn't even so sure, no matter how much he was ready to get back on the court after missing four games because of a high ankle sprain.
"I didn't know if I should do it or not," Nowitzki said.
But Nowitzki was back, scoring 18 points in his unexpected start Wednesday night, and the Mavericks posted a 111-86 victory over the Golden State Warriors that could have big implications in a tight Western Conference playoff race.
"There was already a sense of urgency. ... And then seeing Dirk out there, it was very inspiring," said Jason Terry, who matched a season-high with 31 points. "We were very surprised to see him [start]. But once we saw him out there joking and laughing and smiling, I knew he'd be OK."
Nowitzki had expressed doubts about playing after the morning shootaround, and the final decision wasn't made until he warmed up less than 90 minutes before the game.
Coach Avery Johnson had indicated earlier in the day that the Mavericks were planning to play without Nowitzki. But that may have been part gamesmanship against Warriors coach Don Nelson, who resigned as the Dallas coach in March 2005 and turned the team over to Johnson, his hand-picked successor.
"Yeah, yeah, Nellie taught me that," Johnson said.
Dallas (47-28), seventh in the Western Conference, moved a full game ahead of idle Denver and two games ahead of Golden State (45-30). Only the top eight teams make the playoffs.
The Warriors have consecutive losses for only the second time since going 0-6 to start the season, when Stephen Jackson was suspended. They were also held under 100 points again after having a 37-game streak of hitting the century mark snapped in a 116-92 loss at San Antonio on Tuesday.
"We played two lousy games and ran into two hot teams," Nelson said. "That combination is going to get you beat by 20, if you're lucky."
Nelson called it "the biggest game of the season" for both teams -- there are only seven regular season games left. But Golden State responded with one of its worst performances of the season.
"It's mandatory that we win the rest of them," Jackson said. "We don't want to wait around for other teams to lose."
Josh Howard added 28 points for the Mavericks, while Kidd had a season-high 17 assists with 11 rebounds and five points.
The Mavericks had been 11-10 since getting Kidd from New Jersey at the All-Star break. Dallas was 0-10 against teams with winning records with the All-Star point guard before the victory over the Warriors, which came three nights after a 114-104 loss at Golden State.
Nowitzki, who sprained his ankle and his knee 10 days earlier, moved gingerly when he took shots during warmups. But there were chants of "Dirk! Dirk! Dirk!" just before pregame introductions, then a deafening roar when he was the last starter introduced.
Nelson embraced Nowitzki and tapped him on the head in front of the scorer's table before tipoff.
"The big different was Nowitzki playing," Nelson said. "He was quite an inspiration to them."
While Nowitzki was obviously not at the top of his game (6-of-15 shooting) during his 27 minutes, he twisted and turned moving to the basket several times and didn't appear to have any significant problems with his ankle. He had already said his knee was fine.
"I wasn't moving great out there. I was catching and shooting, or posting up and letting other guys do the work," he said.
Nowitzki didn't touch the ball on the Mavericks' first two possessions, but then had a defensive rebound and missed a 13-foot jumper. On the next possession, he moved inside along the baseline, drawing a foul and hitting both free throws for a 4-2 lead.
Dallas never trailed in the game, going ahead for good on Howard's 15-foot jumper. That was one of three straight baskets on which Kidd had an assist in a span of 90 seconds.
Kidd's 17 assists were seven more than Golden State's entire team. Kidd had an 11-3 advantage at halftime, when the Mavericks led 60-50.
"We need to get our spark back," Davis said. "This is a tough lose, a double lose."
The last time Golden State lost consecutive games was Jan. 2 and 4, at Dallas and against New Orleans. ... Warriors F Mickael Pietrus missed his seventh straight game because of a right groin injury. ... Dallas had a season-high 56 rebounds. Erick Dampier had 11 to match Kidd's total.